Every 15 seconds someone in the United States will
suffer a head injury resulting in significant brain damage. Of
the survivors, approximately 90,000 per year will experience an
enduring loss of function due to the consequent brain trauma.
Additionally, many individuals suffer similar functional losses
due to a wide variety of neurological disorders such as Alzheimer's
Disease, Vascular Dementia, Multiple Sclerosis, etc.
The application of Virtual Reality technology for the cognitive assessment and rehabilitation of persons with acquired brain injury and neurological disorders could serve to revolutionize the study of brain/behavior relationships as well as produce treatment options unavailable with traditional methods. The development of this field will require the merging of knowledge from a variety of disciplines including (but not limited to) neuropsychology, educational theory and technology, human factors, and computer science. Basic questions pertaining to the structure of human cognitive processes, optimal levels of immersion to facilitate learning, transfer of training factors, and "cybersickness" concerns, etc. will need to be considered in an integrative fashion to properly advance these VR applications. The proposed presentation will describe how Virtual Reality (VR) can be used to facilitate cognitive assessment and rehabilitation. Our talk would briefly address the theoretical basis for these VR applications, review the progress in these areas, discuss future applications, and describe our ongoing work developing a mental rotation/spatial skills cognitive assessment and training system.
Effective neuropsychological assessment is a prerequisite for both the treatment and scientific analysis of any neurologically-based cognitive impairment. Virtual reality technology offers the potential to develop human performance testing environmehat could supplement traditional procedures and improve accepted standards for psychometric reliability and validity. The neuropsychological assessment of persons with acquired brain injury and neurological disorders serves to aid in determining a diagnosis; assist in providing a starting point for the design of rehabilitative strategies; and create data for the scientific understanding of brain functioning through the examination of measurable sequelae following different types of brain trauma. Virtual reality offers unparalleled opportunities for cognitive processes to be quantified. This presentation will address the applicability of virtual reality approaches to neuropsychological assessment in terms of reliability and validity issues. The assessment of cognitive functioning hinges on the ability to reliably and validly measure behaviors that are associated with specific brain activity. The current state of the art in neuropsychological assessment involves the use of paper and pencil tests. The reliability of these instruments is adversely affected by a number of factors that could be improved with the use of VR. These include differences in testing environment, differences in test administration procedures and the effect of different test administrators. VR could potentially improve the reliability of neuropsychological assessment by allowing for more consistent manipulation of complex test stimuli. It will also allow for more precise measurement of participant responses.
The validity of paper and pencil tests could also be greatly improved with VR technology. The primary means for improving validity would be the ability to measure responses to stimuli much more precisely. The quantification of more discrete behavioral responses will allow for the identification of more specific cognitive domains. With VR technology, all aspects of the subjects' responses could be quantified. Information on latency, solution strategy and visual field preferences would be recorded. With appropriate analytic techniques, the general constructs could be refined to its component constructs. This methodology could also be used to evaluate essential cognitive domains including attention, memory, visuospatial skills, executive functioning, problem solving and critical thinking. Further, VR would allow for cognition to be tested in situations that are "ecologically" valid, meaning subjects could be evaluated in an environment that simulates the real world, not a contrived testing environment. Thus results will have greater clinical relevance and would have direct implications for the development of cognitive training systems.
Over the last 25 years, neuropsychologists, occupational therapists, special educational professionals, and other rehabilitation specialists have developed cognitive rehabilitation techniques aimed at the restoration of cognitive skills and the training of functional abilities in persons with neurologically-based brain injury. Cognitive rehabilitation (CR) has been defined as "...the therapeutic process of increasing or improving an individual's capacity to process and use incoming information so as to allow increased functioning in everyday life." (Sohlberg and Mateer, 1989). Cognitive rehabilitative methods have been applied to a wide range of thinking abilities from the most basic processes of attention training to the higher mental functions of logical reasoning. Generally, the most often addressed cognitive areas include attentional abilities, memory, visual and auditory processing, language, spatial skills, executive functioning (planning, initiating, and maintaining goal-oriented behaviors), logical reasoning, problem solving, and critical thinking.
Two primary CR orientations have developed--the restorative and functional approaches. The restorative approach (also called direct intervention or process-specific) has as a goal, the restoration of specific cognitive functions by retraining new fonal systems in the brain to take over for areas of lost cognitive function. This is accomplished via a drill and practice methodology which is hypothesized to stimulate some type of neural growth or reorganization. For example, in training attentional abilities, the person would perform tasks that require them to focus on, sustain focus on, or selectively attend to, basic information within their initial baseline capacity for functioning. As their performance improves with practice, the attentional load is increased gradually. Attentional components are expected to improve much like a muscle gets stronger with increased exercise. Another restorative technique, Prospective Memory Training, requires the person to remember an activity to perform at a later time and as the person begins to demonstrate success after brief time periods, the time interval to perform is gradually lengthened. It is believed that by having a person practice "storing and holding" information for increased time intervals, that they will "build" a "stronger" memory. Some of the often cited criticisms of these methods is that they rely on test materials or tasks that are essentially artificial, are of little relevance to "real-world" functional cognitive challenges, and that the learning does not generalize to performance outside the training environment (Prigatano et al., 1984).
The functional approach (also termed compensatory or alleviational) focuses on teaching "real-life" skills utilizing whatever alternative preserved abilities that exist, to allow the individual to perform essential activities. Functional approachesrally focus on the activities of daily living (ADL's), such as remembering a sequence of events to prepare for work in the morning or a set of structured steps for completing day-to-day activities (meal preparation, job tasks, grooming routines, etc.). Often this approach utilizes compensatory methods, such as teaching a person to use a variety of assistive memory tools or tactics. For memory rehabilitation, compensatory methods fall into two categories: external and internal. An external aid would include memory notebook systems, electronic memory devices, alarms, calendars, reminders posted in different positions around the house, standardized locations for storing regularly needed items (car keys on a hook by the front door). Internal aids usually consist of learning mnemonic strategies, such as acronyms, peg word systems, and associative imagery. Criticism of functional methods include foremost, that the learning of standard stereotyped behaviors to accomplish ADL's assumes that the person lives in a static world where life demands do not change and that the person will not need to creatively adjust to changing circumstances (what if the patient "forgets" to bring his "memory" notebook with him?).
Implied within both the restorative and functional approaches to cognitive rehabilitation are differential primary goals. The restorative approach places as it's primary objective, the retraining of individuals on how to think, whereas the primary eis of the compensatory approach is to teach individuals how to do. While most rehabilitation programs provide a mixture of techniques from both of these orientations, the issues surrounding the relative pragmatic value of each are often hotly debated.
The use of VR technology for the rehabilitation of individuals with brain trauma offers considerable promise for both the restorative and functional approaches to CR. It is proposed that VR technology could serve to remedy the major weaknesses of boe restorative and functional approaches and actually produce a systematic treatment method which would integrate the best features from both methods. In essence, it may be possible for a VR application to provide systematic restorative training within the context of functionally relevant simulated environments which optimize the degree of generalization or transfer of learning to the person's real world environment.
In a previous paper, Rizzo & Buckwalter (1995) suggested that VR is optimally suited to meet the criteria for the design of both restorative and functional rehabilitation tasks. The nature of immersive computer simulations allow that virtual worlds could be designed which are ecologically relevant to the functional CR process. Further, within these simulations, cognitive demands can be presented which are specific, adjustable in terms of difficulty level, hierarchically presented contingent upon success, and provide for immediate performance feedback and guidance to the patient; all necessary characteristics of a restorative CR approach. Also, with many neurological disorders, and in cases of acquired brain injury, it is observed that procedural or skill based learning is often relatively preserved (Butters et al., 1987; Cohen & Squire, 1980). An interactive immersive VR approach is optimally poised to exploit this spared procedural learning capacity and could accomplish this within ecologically valid and scientifically controlled training environments.